The present territories of Isulan formerly belonged to the municipalities of
Koronadal and
Dulawan. The municipality of Koronadal was created under E.O. No. 82 dated August 8, 1947 by Pres. Manuel L. Roxas. On March 10, 1953, the municipality of
Norala was created by virtue of E.O.NO.572, whose territorial jurisdiction was taken from the municipality of
Koronadal. Datu Kudanding Camsa in the latter part of 1956 initiated the creation of another municipality to be taken from the Municipality of Norala. On March 20, 1957, Engr. Jose M. Ancheta of the Bureau of Public Highways of Cotabato made its first endorsement to the provincial board and laid down the proposed boundaries of the new municipality. Acting on this report, the provincial board of Cotabato thru Resolution No. 316 series of 1957, petitioned the President of the Philippines to create the proposed municipality. Executive Order No. 266, pursuant to section 68 of the Administrative Code, issued and signed by the then President
Carlos P. Garcia on August 30, 1957, creating the municipality of Isulan, whose territorial jurisdiction was taken from the municipality of
Norala, South Cotabato, and Dulawan, Cotabato. With the creation of the municipality of Isulan, Kalawag became the seat of its government. The municipal government officially functioned on September 12, 1957, with the appointment of its municipal mayor Datu Suma Ampatuan who served until 1967.
The Kalawag Settlement In 1951, the Board of Directors of the Land Settlement and Development Cooperation (LASEDECO) started the opening of a settlement in an area formerly under the jurisdiction of the National Land Settlement Association (NLSA) as a reservation. The LASEDECO had surveyed and parceled out home and farm lots and constructed municipal and barrio roads and installed electrical light generators. It had brought-in hundreds of farm tractors which uprooted big trees, cleared obstruction, planned, cleaned and harrowed the wide stretches of the area. What was once a marshy and wild expanse inhabited by snakes, crocodiles, wild cattle, swine, and deer had welcomed the first sprout of seedlings of corn and rice, thus blanketed the horizon in endless green. When a group of 72 World War II Veterans, led by Venancio Magbanua, Post Commander of Norala had come and settled in the area, on September 7, 1950, a Kalawag root crop used as food coloring was found out abundantly growing. Then, the early settlers decided to call and register the settlement as "Kalawag Settlement District of LASEDECO". The area comprising the town site covers approximately 400 hectares. Immigrants from Visayas and Luzon had now come in shiploads. The most numerous batch was the "PACSA" group headed by Pedro Gabriel and Bienvenido Pamintuan otherwise known as the "Presidential Assistance Commission on Social Amelioration of the President
Ramon Magsaysay. His group consisted of the erstwhile and rebellious surrenderees belonging to HUKBALAHAPs from
Pampanga. On June 21, 1969, President Marcos, signed R.A. No. 5960, creating the municipality of
Bagumbayan which cost Isulan more than 85% of its original land area. But of the original land area of 336,000 hectares, only 49,551 hectares were left and the 48 barrios were reduced to 17. Upon the passage of H.B. No. 5020 dividing the province of Cotabato, the Municipal Council of Isulan passed Resolution No. 17 dated May 31, 1972, requesting Congressman Salipada K. Pendatun and Gov. Carlos B. Cajelo that Isulan be made a capital town. On November 22, 1973, P.D. No. 341 was issued dividing Cotabato provinces, namely;
Sultan Kudarat,
Maguindanao and
North Cotabato. At the same time, Isulan, which is in the center of the new province, was made its capital. ==Geography==